Einstein believed that black holes didn't really exist. But they do: that much we know. We don't know much else about them.

Think falling into a black hole is easy? Think again. These cosmic beasts may have gravity beyond imagination, but getting ...

Whether a galactic environment has the right conditions for habitable planets to form could depend on how the black hole in that galaxy is rotating.

“This is all within 16,000 light-years of the black hole.” These strange features may be more than just cosmic debris. Some could be small satellite galaxies falling into 3C 273, feeding the ...